A. Field of Invention
This invention pertains to the art of methods and apparatuses related to snowplows and more specifically to methods and apparatus related to limiting the pivoting motion of the snowplow.
B. Description of the Related Art
It is well known in the art to provide a snowplow on the front of a vehicle for displacing snow, sleet, ice and the like along a roadway, driveway or other ground surface. Generally, a snowplow assembly will include a plow blade that is used to contact the snow and a mount assembly that is used to mount the snowplow mechanism to the vehicle. Many snowplow assemblies pivotally attach the plow blade to the mount assembly allowing the blade to pivot about a vertical pivot axis and direct plowed snow to either side of the vehicle path. The mount assemblies are often pivotally attached to a vehicle for selectively raising and lowering the snowplow assembly using hydraulic controls located in the vehicle. The plow blade may also be pivotally attached to the mount assembly allowing the plow blade (or a portion of the blade) to pivot about a horizontal mounting axis. Springs may connect between the plow blade and the mount assembly for biasing the plow blade in an upright position and for dampening the rotational movement about the horizontal mounting axis when the plow blade encounters an obstacle.
It is also known in the art to provide one or more actuators with snowplow assemblies for use in pivoting the plow blade about the vertical pivot axis. Such actuators are commonly hydraulic cylinders. Some of these known snowplow assemblies also include one or more stops for limiting the pivotal motion of the plow blade around the vertical pivot axis. These pivotal stops can protect the actuator from over-extension, can protect the actuator from loads imparted on the plow blade from obstacles, or can provide additional support for the plow blade when the plow blade is in a fully pivoted position.
While known pivotal stops generally work well for their intended purpose, they have disadvantages. One disadvantage is that known pivotal stops do not adequately distribute the loads that they incur to the mount assembly. Another problem is that known pivotal stops are known to contribute to alignment problems for the actuators and the mount assembly/snowplow frame interface. Therefore, what is needed is a mount assembly with a robust pivotal stop that can distribute large loads and maintain alignment during typical snowplow use conditions.